Re: [PATCH] device_tree: Fix compiler error

["Michal Prívozník" <mprivozn@redhat.com>]

On 11/9/21 9:38 AM, Richard Henderson wrote:
> On 11/8/21 9:07 PM, Stefan Weil wrote:
>> A build with gcc (Debian 10.2.1-6) 10.2.1 20210110 fails:
>>
>> ../../../softmmu/device_tree.c: In function ‘qemu_fdt_add_path’:
>> ../../../softmmu/device_tree.c:560:18: error: ‘retval’ may be used
>> uninitialized in this function [-Werror=maybe-uninitialized]
>>    560 |     int namelen, retval;
>>        |                  ^~~~~~
>>
>> This is not a real error, but the compiler can be satisfied with a
>> small change.
>>
>> Fixes: b863f0b75852 ("device_tree: Add qemu_fdt_add_path")
>> Signed-off-by: Stefan Weil <sw@weilnetz.de>
> 
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
> 
> Though I think there's a good deal that could be cleaned up about this
> function:
> 
> (1a) Remove the unused return value?
>      The single use does not check the return.
> 
> (1b) Don't attempt to return a node, merely a success/failure code.
>      Certainly the local documentation here could be improved...
> 
> (1c) Return parent; make retval local to the loop.
> 
> (2) Merge p and path; there's no point retaining the unmodified parameter.
> 
> (3) Move name and namelen inside the loop.


(4) swap if() bodies?

if (retval == -FDT_ERR_NOTFOUND) {
} else if (retval < 0) {
}

Michal